Time Interval Measurement - Racal Instruments 9901 Maintenance Manual

TIME INTERVAL-B (SINGLE
LINE)
3.8
In
this
mode
the instrument
is
effectively serving as a
stop-watch.
Start
and
Stop
signals are
supplied from
an
input on the
'B'
channel
or
by
operating the
manual
START
and
STOP
buttons.
The
time
interval
is
measured by counting clock
units
derived
from
the
frequency
standard.
3.9 The
0.1 microsecond output from a
10
MHz
frequency
reference
is
applied
to
the
time base
decades and
a
suitable
clock
unit
is
selected
by
depressing
an
appropriate
Range
push-button. These clock
pulses are
then coupled
to
the signal input of
the
main
gate
and
are totalled
in
the counter decades
during the
interval
between
the
Start
and
Stop
signals.
At
the
end
of the
count
the
total
of time
units
is
displayed.
The time
value
of the
chosen
unit
is
marked
beside the
Range
button
('n').
TIME INTERVAL B-A (DOUBLE
LINE)
3.10
The
operating principle
is
the
same
as for single line, except
that the
start
and
stop signals are
on
separate
inputs.
The
display
will
read
the true
time
interval
between
events
on
the separate
'A'
and
'B'
channels.
Time Interval
Measurement
Fig. 3.3
3-4
9901 Vol
.
2